Sustainable material cycle for steel

Steel is often advertised as fully recyclable, but the reality is different: Every year, Europe exports steel scrap in the order of magnitude of German steel consumption to newly industrialising countries. The research focusses on the material cycle of steel production.

Our companies' consumption of raw materials has reached an all-time high. In view of limited resources, the question is pressing: How long can the planet meet our needs? One answer to this question lies in intelligent material design and closed material cycles in order to minimise losses in material and added value. Researchers at the Karlsruhe Institute of Technology (KIT) are focussing on the material cycle of steel production in the EU project NANO-S-MART, which has now been launched.

Impurities make steel unusable in Europe

Steel is regarded as a ‘model pupil’ in the recycling industry and is often touted as fully recyclable. But the reality is different: Every year, Europe exports steel scrap in the order of magnitude of German steel consumption to newly industrialising countries. ‘The required material qualities in Europe can no longer be achieved because the recycling process concentrates impurities in the steel’, says Professor Christoph Kirchlechner from the Institute for Applied Materials at KIT. ‘Our project aims to deepen understanding of how harmful elements are handled in the recycling process and pave the way for more sustainable material cycles’.
In this way, the researchers hope to help reduce the carbon footprint of steel production. To achieve this aim, impurities such as copper are to be integrated into the steel in such a way that they do not cause any damage. ‘A challenging task, as even a single atomic layer in the wrong place can cause the material to fail’, says Kirchlechner. His research group will focus on the failure of individual phases and phase interfaces at the micro level. For this purpose, samples just a few micrometres in size are tested under an electron microscope.
The research network, which is coordinated by the Asociación Centro Tecnológico CEIT, includes the Max Planck Institute for Sustainable Materials, the Onderzoekscentrum voor Aanwending van Staal and the University of Ghent in addition to the KIT. The EU is funding the project with about 3.1 million euros for four years.
Source: KIT